HydroBASINS lev08 watershed · #2080552810
Bassin de l'Ance
A watershed (drainage basin) is not a body of water — it is the land area where rainfall converges towards a single river that eventually reaches the sea (or an endorheic basin). Boundaries follow ridgelines.
Crosses 2 administrative regions : Haute-Loire, Lozère
Sub-basin area
233,1km²
Upstream area
233,1km²
Discharge
3,02m³/s
Mean elev.
1 160m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
2 dept-equivalent regions (GADM L2)
- 144.9 km²62.0% of basin
- 88.6 km²38.0% of basin
22 communes (GADM L5)Available for FRA, RWA
- Chanaleilles41.91 km²85% commune
- Saint-Paul-le-Froid38.59 km²88% commune
- Thoras37.78 km²100% commune
- Saint-Symphorien27.55 km²81% commune
- Saint-Préjet-d'Allier19.60 km²81% commune
- Saugues11.87 km²15% commune
- Esplantas8.26 km²82% commune
- Chambon-le-Château7.95 km²100% commune
- Croisances7.49 km²100% commune
- Vazeilles-près-Saugues6.96 km²100% commune
- La Panouse5.75 km²15% commune
- Sainte-Eulalie4.37 km²20% commune
- Saint-Vénérand3.87 km²40% commune
- Monistrol-d'Allier3.78 km²14% commune
- Alleyras2.12 km²8% commune
- Grandrieu1.97 km²3% commune
- Saint-Denis-en-Margeride1.30 km²3% commune
- La Villedieu0.97 km²4% commune
- Saint-Christophe-d'Allier0.76 km²4% commune
- Grèzes0.52 km²1% commune
- Le Malzieu-Forain0.11 km²0% commune
- Lajo0.09 km²0% commune
5 intersecting protected areas
Haut Val d'Allier
IUCN Not ReportedSpecial Protection Area (Birds Directive)
23.17 km² overlap
Montagne de la Margeride
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
22.34 km² overlap
Gorges de l'Allier et affluents
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
12.92 km² overlap
Sommets et versants orientaux de la Margeride
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
7.23 km² overlap
Biotope Protection Order
0.36 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 745 distinct species · 39 909 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 28 species (selected proportionally per kingdom among those with at least one documented interaction here) to keep the graph readable. Hover for details, click to explore the full ecosystem of a species.
ℹ️ The territory contains many more species than displayed and all their documented interactions: the graph is intentionally the structural skeleton (top-N species by composite local score, edges filtered by Serrano 2009 disparity filter α=0.2).
Indicateurs du tissu écologique
Tissu écologique de Bassin de l'Ance : 21 espèces + 7 bulles famille, 53 interactions GloBI documentées sur 6 types (connectance 14.0%, filtre Serrano α=0.2). Les 7 bulles regroupent des espèces visuellement absorbées par famille (≥3 espèces visibles).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydroclimate (BasinATLAS lev08)
Mean T°
7,0°C
Annual rain
818mm
Moisture idx (CMI)
0,05
Runoff
417mm/an
PET
769mm
AET
632mm
Mean slope
7,1°
Water table
468cm
Forest
87%
Crops
1%
Urban
0%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)